1. Field of the Invention
The present invention relates to a reconfigurable porous technology for fluid flow control system and more particularly to reconfigurable porosity fluid flow control system for vehicles such as aircraft, missiles, ground and water vehicles to improve the performance of such vehicles. The present invention further relates to a method of operating the reconfigurable porosity fluid flow control system.
2. Technical Background
Conventionally, technology to control lift or drag on vehicles such as aircraft, missiles, ground vehicles and water vehicles utilizes various movable mechanical structures. These structures include fins, spoilers, canards and associated structural and actuation hardware to alter, vary and control lift or drag. These control structures have required significant payload and volume in order to house both the control structure and associated hardware imposing substantial weight, volume, and power requirements, thereby reducing the performance of the vehicle.
An example of this has been where conventional control surfaces reduced the effective payload volume of a missile that could be potentially used for other systems such as an inertial measurement unit; a global positioning system; and/or additional rockets, explosives and/or other payload. The additional weight and drag of these control surfaces also reduced the range and efficiency of the missile. Furthermore, canards and fins create significant drag, pushing the missile weapons designer into a Faustian bargain, i.e., trading maneuverability and accuracy for range and payload capacity. Similar problems exist with the use of conventional control surfaces on other types of vehicles.
Additionally, conventional control surfaces which utilize hydraulic, pneumatic, and other mechanical devices have been subject to various static and dynamic forces, loads, pressures, stresses, strain, wear and fatigue which result in reducing the life and accelerated failure of these various components. These various static and dynamic forces, loads, pressures, stresses, strain, wear and fatigue may have been also transferred or otherwise transmitted to portions of the vehicle structure resulting in a reduction in the useful life of the vehicle structure itself.
More recently, vehicle designers have overcome some of these limitations with the use of porosity to control the transfer of fluid flow through one or more surfaces on various regions of a vehicle. Generally with these porous systems, the designers have used a static system where the pores or openings, and the pneumatic substructure connecting the pores or openings does not change due to dynamic conditions on the vehicle surface. Even more recently, aircraft airfoil designers have proposed airfoil systems, which allow for a somewhat limited control of the fluid flow by the use of changeable configurations of pores or openings, or of the underlying pneumatic substructure. These systems, however, have been limited from effectively operating in the changing conditions of a rapidly evolving, dynamic environment most vehicles experience during normal operations. This is because the passive porous systems do not change in response to the highly evolving surface conditions, and the porous systems with changeable configurations are reconfigured too slowly and without the resolution (due to the small number of configurations which are achievable with these systems) needed for the fluid flow dynamics of most vehicles' surfaces.
Accordingly, it is the object of this invention to provide a reconfigurable porosity system in which the pores on the surface are individually addressable, and highly reconfigurable.
Another object of the present invention is to provide a reconfigurable porosity system in which the pores are reconfigurable in real time.
Still another object of the present invention is a method for operating such a reconfigurable porosity fluid flow control system.